Insert the flange (20) in its housing in the fuel tank.
Apply prescribed threadlocker to the screws (9) and tighten to a torque of 6 nm +/- 10% (sect. 3 - 3, Frame torque settings), following the indicated order.

Replacing the tank flange and fuel sensor
Refitting the fuel tankRemoving the silencer
Loosen the clamp (38) that retains the silencer (4) to the complete exhaust
system.
While holding the nut (8), loosen the screw (1) and remove the silencer (4)
from the motorcycle.
Loosen the screws (40) and remove the silencer guard (41).
...
Refitting the engine
Refitting is the reverse of removal.
Important
Apply recommended grease and tighten the special screws (6) to a torque of
60 nm +/- 5% (sect. 3 - 3, Frame torque
settings).
Tighten the nuts (3) to a torque of 48 nm +/- 5% (sect. 3 - 3, Frame torque
settings).
Warning
For the assembly seque ...
Lubricating cables and joints
Check the outer sheath of the throttle control and cold start
lever cables for damage at regular intervals. The outer plastic
cover should not be flattened or cracked. Operate the
controls to make sure the inner cables slide smoothly inside
the outer sheath: if you feel any friction or catching, ...